The present invention relates to an exhaust treatment component arrangement for an off-road vehicle such as an agricultural tractor.
Tier 4 interim emissions standards, which are expected to take effect for off-highway vehicles in 2011, will require all off-highway vehicles to manage Particulate Matter (PM) and NOx levels. It is expected that this will require some combination of engine control and after-treatment devices. In 2014, it is expected that final Tier 4 regulations will require further NOx reductions. Presently, it appears that both a diesel particulate filter and some sort of NOx reduction device will be required in 2014.
U.S. Pat. No. 7,017,338, issued 28 Mar. 2006 to Nieuwstadt, shows a diesel emissions control system which includes an oxidation catalyst, a particulate filter and a NOx aftertreatment catalyst, all connected in series upstream of a muffler. U.S. Pat. No. 6,907,858, issued 21 Jun. 2005 to Miura, shows a diesel engine which includes an oxidation catalyst, NOx trapping catalytic converter and a diesel particulate filter, all connected in series. However, such exhaust treatment devices are quite large—with total volumes of about 10 times the engine displacement, and neither of these patents shows how to arrange these large components on a vehicle without interfering with operator vision.